ERYC SPRINKLES
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ERYC SPRINKLES (ERYC SPRINKLES).
Erythromycin binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis by blocking the translocation of peptidyl-tRNA. It may also act as a motilin receptor agonist, enhancing gastrointestinal motility.
| Metabolism | Primarily metabolized by hepatic cytochrome P450 3A4 (CYP3A4) enzymes. Erythromycin is also a potent inhibitor of CYP3A4, leading to drug interactions. Excretion occurs mainly via bile and feces, with minimal renal elimination. |
| Excretion | Primarily biliary (fecal) elimination (60-80% as unchanged drug) with approximately 5-15% renal excretion of active drug. |
| Half-life | 1.5-2.0 hours in adults with normal renal function; prolonged in neonates (2-4 hours) and patients with hepatic impairment. |
| Protein binding | 70-90% bound, primarily to albumin. |
| Volume of Distribution | 0.5-1.0 L/kg; extensive distribution into tissues, but minimal CNS penetration. |
| Bioavailability | Oral (erythromycin base): 25-40% (due to acid lability and first-pass metabolism). |
| Onset of Action | Oral (capsule sprinkle): 1-2 hours for therapeutic serum concentrations. |
| Duration of Action | Approximately 6-8 hours for bacteriostatic effect; clinical duration depends on infection site and susceptibility. |
250-500 mg orally every 6 hours (or 333 mg every 8 hours) for adults; maximum 4 g/day.
| Dosage form | CAPSULE, DELAYED REL PELLETS |
| Renal impairment | For CrCl < 30 mL/min (or < 10 mL/min per some sources): 50% reduction in dose or interval extended to every 12-24 hours. For CrCl 10-30 mL/min: 250-500 mg every 12 hours. Hemodialysis: Dose after dialysis. |
| Liver impairment | No specific guidelines; caution in severe hepatic impairment due to potential hepatotoxicity. |
| Pediatric use | Neonates <7 days: 25 mg/kg every 12 hours; neonates 7-28 days: 25 mg/kg every 8 hours; infants/children: 30-50 mg/kg/day in 4 divided doses; maximum 2 g/day. For severe infections, up to 75-100 mg/kg/day in 4 divided doses. |
| Geriatric use | No specific adjustment but monitor renal function; use lowest effective dose due to age-related renal decline. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ERYC SPRINKLES (ERYC SPRINKLES).
| Breastfeeding | Erythromycin is excreted into breast milk in small amounts. The milk-to-plasma (M/P) ratio is approximately 0.5. Peak milk concentrations occur 1-2 hours after a dose. The relative infant dose is estimated at 2% of the maternal weight-adjusted dose, which is considered low. Adverse effects in breastfed infants are rare but may include gastrointestinal disturbances (e.g., diarrhea, vomiting) and potential for alteration of infant gut flora. Theoretical risk of IHPS in infants less than 2 months of age exists; however, cases have been reported primarily with maternal oral use in older infants. The American Academy of Pediatrics considers erythromycin compatible with breastfeeding. |
| Teratogenic Risk |
■ FDA Black Box Warning
Increased risk of infantile hypertrophic pyloric stenosis (IHPS) when used in neonates up to 30 days of age. Elderly patients and those with preexisting cardiac disease may have increased risk of QT prolongation and sudden cardiac death.
| Serious Effects |
["Hypersensitivity to erythromycin or any macrolide","Concomitant use with potent CYP3A4 inhibitors (e.g., cisapride, pimozide, some statins) due to increased risk of life-threatening arrhythmias","Concomitant use with ergotamine or dihydroergotamine (ergotism risk)","Congenital QT prolongation or known history of torsades de pointes"]
| Precautions | ["QT prolongation and risk of ventricular arrhythmias (especially with other QT-prolonging drugs, electrolyte disturbances, bradycardia)","Severe hepatotoxicity (cholestatic hepatitis) with estolate salt (rare with base form)","Increased risk of infantile hypertrophic pyloric stenosis in neonates","Clostridium difficile-associated diarrhea (CDAD)","Myasthenia gravis exacerbation","Ototoxicity (usually reversible with high doses, especially in renal impairment)"] |
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| Erythromycin (ERYC SPRINKLES) is generally considered low risk for teratogenicity. Animal studies show no evidence of fetal harm. Human data from large cohort studies do not indicate an increased risk of major birth defects with exposure during the first trimester. However, there is a potential association with pyloric stenosis in neonates exposed during late pregnancy or near delivery, specifically infantile hypertrophic pyloric stenosis (IHPS). Risk is highest with exposure after 32 weeks gestation or within 2 weeks of delivery. No specific teratogenic risks are identified for the second or third trimester beyond the risk of IHPS. |
| Fetal Monitoring | For maternal monitoring: assess liver function (ALT, AST, bilirubin) and renal function (serum creatinine) if prolonged therapy. Monitor for gastrointestinal side effects (nausea, vomiting, diarrhea) and QT interval prolongation (ECG) especially in patients with pre-existing cardiac conditions or electrolyte imbalances. Fetal/neonatal monitoring: during late pregnancy (especially after 32 weeks), observe newborn for signs of infantile hypertrophic pyloric stenosis (projectile vomiting, irritability, weight loss) for the first 6 months of life. No routine fetal monitoring is required otherwise. |
| Fertility Effects | Erythromycin has no known adverse effects on fertility in animal studies or human data. It does not interfere with conception, implantation, or gamete function. No specific effects on menstrual cycle or spermatogenesis have been reported. |